<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>响应式</title>
    <link  rel="stylesheet" href="link.css"media="only screen and (max-width:480px)"/>
    <style>
       @media screen and (min-width:480px){
            body{
                background-color: blue;
            }
        }

    </style>
</head>
<body>
fds
</body>
</html>